Modernized Minpack release candidate

Announcements
1

We are now staging the first release of the modernized Minpack version at

We are interested in feedback for the Fortran package (supported via fpm or meson), as well as the C and Python bindings. Let us know if you find something that is not working as expected.

To use this version of Minpack with fpm it requires nothing but a dependency in the package manifest

[dependencies]
minpack.git = "https://github.com/fortran-lang/minpack"

For meson projects you can get the minpack dependency via

minpack_dep = dependency('minpack', fallback: ['minpack', 'minpack_dep'])

To use mesons subprojects include a wrap file with the following content in subprojects/minpack.wrap

[wrap-git]
directory = minpack
url = https://github.com/fortran-lang/minpack
revision = head

Finally, for Python projects we offer a shortcut via meson-python to directly build the Fortran projects and the Python bindings

pip install https://github.com/fortran-lang/minpack/releases/download/v2.0.0-rc.1/minpack-2.0.0-python-sdist.tar.gz

We didn’t upload Minpack to PyPI yet, because we want to gather some experience on the usability of meson-python as build backend first before we fully commit to it. The disadvantage of this build setup is obviously that you cannot use the Minpack installation in Fortran anymore :wink:

12 Likes
2

I was looking for inspiration on how to develop a C API for a Fortran routine and came across with this project.
The c-bindings are defined in minpack_capi.f90. I guess I understand most of the code, but I wonder why the interfaces to the problem functions (e.g. minpack_func) are declared public. Is that really necessary? Why so?
Thanks.

3

It’s useful for the case where the function is selected at runtime:

// For C
minpack_func f = condition ? &funa : &funb;

! In Fortran
procedure(minpack_func), pointer :: f

If (condition) then 
   f => funa
else
   f => funb
endif

Or if you want to write a procedure that takes a MINPACK compatible function as an argument.

4

I realize I need to restate the question more precisely. I understand the use mentioned by @ivanpribec.

What intrigues me is that the companion header file minpack.h includes a typedef definition for the problem functions. Isn’t this somehow equivalent to the interfaces? Isn’t this “double definition” redundant?

5

It’s necessary because we define the procedures on the Fortran side, but you need the declaration on the C side.